aboutsummaryrefslogtreecommitdiff
path: root/vendor/tiff/src/encoder/compression/deflate.rs
diff options
context:
space:
mode:
Diffstat (limited to 'vendor/tiff/src/encoder/compression/deflate.rs')
-rw-r--r--vendor/tiff/src/encoder/compression/deflate.rs83
1 files changed, 83 insertions, 0 deletions
diff --git a/vendor/tiff/src/encoder/compression/deflate.rs b/vendor/tiff/src/encoder/compression/deflate.rs
new file mode 100644
index 0000000..5e7a261
--- /dev/null
+++ b/vendor/tiff/src/encoder/compression/deflate.rs
@@ -0,0 +1,83 @@
+use crate::{encoder::compression::*, tags::CompressionMethod};
+use flate2::{write::ZlibEncoder, Compression as FlateCompression};
+use std::io::Write;
+
+/// The Deflate algorithm used to compress image data in TIFF files.
+#[derive(Debug, Clone, Copy)]
+pub struct Deflate {
+ level: FlateCompression,
+}
+
+/// The level of compression used by the Deflate algorithm.
+/// It allows trading compression ratio for compression speed.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+#[non_exhaustive]
+pub enum DeflateLevel {
+ /// The fastest possible compression mode.
+ Fast = 1,
+ /// The conserative choice between speed and ratio.
+ Balanced = 6,
+ /// The best compression available with Deflate.
+ Best = 9,
+}
+
+impl Default for DeflateLevel {
+ fn default() -> Self {
+ DeflateLevel::Balanced
+ }
+}
+
+impl Deflate {
+ /// Create a new deflate compressor with a specific level of compression.
+ pub fn with_level(level: DeflateLevel) -> Self {
+ Self {
+ level: FlateCompression::new(level as u32),
+ }
+ }
+}
+
+impl Default for Deflate {
+ fn default() -> Self {
+ Self::with_level(DeflateLevel::default())
+ }
+}
+
+impl Compression for Deflate {
+ const COMPRESSION_METHOD: CompressionMethod = CompressionMethod::Deflate;
+
+ fn get_algorithm(&self) -> Compressor {
+ Compressor::Deflate(self.clone())
+ }
+}
+
+impl CompressionAlgorithm for Deflate {
+ fn write_to<W: Write>(&mut self, writer: &mut W, bytes: &[u8]) -> Result<u64, io::Error> {
+ let mut encoder = ZlibEncoder::new(writer, self.level);
+ encoder.write_all(bytes)?;
+ encoder.try_finish()?;
+ Ok(encoder.total_out())
+ }
+}
+
+#[cfg(test)]
+mod tests {
+ use super::*;
+ use crate::encoder::compression::tests::TEST_DATA;
+ use std::io::Cursor;
+
+ #[test]
+ fn test_deflate() {
+ const EXPECTED_COMPRESSED_DATA: [u8; 64] = [
+ 0x78, 0x9C, 0x15, 0xC7, 0xD1, 0x0D, 0x80, 0x20, 0x0C, 0x04, 0xD0, 0x55, 0x6E, 0x02,
+ 0xA7, 0x71, 0x81, 0xA6, 0x41, 0xDA, 0x28, 0xD4, 0xF4, 0xD0, 0xF9, 0x81, 0xE4, 0xFD,
+ 0xBC, 0xD3, 0x9C, 0x58, 0x04, 0x1C, 0xE9, 0xBD, 0xE2, 0x8A, 0x84, 0x5A, 0xD1, 0x7B,
+ 0xE7, 0x97, 0xF4, 0xF8, 0x08, 0x8D, 0xF6, 0x66, 0x21, 0x3D, 0x3A, 0xE4, 0xA9, 0x91,
+ 0x3E, 0xAC, 0xF1, 0x98, 0xB9, 0x70, 0x17, 0x13,
+ ];
+
+ let mut compressed_data = Vec::<u8>::new();
+ let mut writer = Cursor::new(&mut compressed_data);
+ Deflate::default().write_to(&mut writer, TEST_DATA).unwrap();
+ assert_eq!(EXPECTED_COMPRESSED_DATA, compressed_data.as_slice());
+ }
+}